- 一个要点,就是使用它储存的对象,必须 implement Serializable,否则会报错
import android.app.Activity;
import android.content.SharedPreferences;
import android.util.Base64;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
/**
* SharedPreferences工具类,可以保存object对象
* <p>
* 存储时以object存储到本地,获取时返回的也是object对象,需要自己进行强制转换
* <p>
* 也就是说,存的人和取的人要是同一个人才知道取出来的东西到底是个啥 ^_^
*/
public class SharedPreferenceUtil {
/**
* writeObject 方法负责写入特定类的对象的状态,以便相应的 readObject 方法可以还原它
* 最后,用Base64.encode将字节文件转换成Base64编码保存在String中
*
* @param object 待加密的转换为String的对象
* @return String 加密后的String
*/
private static String Object2String(Object object) {
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
ObjectOutputStream objectOutputStream = null;
try {
objectOutputStream = new ObjectOutputStream(byteArrayOutputStream);
objectOutputStream.writeObject(object);
String string = new String(Base64.encode(byteArrayOutputStream.toByteArray(), Base64.DEFAULT));
objectOutputStream.close();
return string;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
/**
* 使用Base64解密String,返回Object对象
*
* @param objectString 待解密的String
* @return object 解密后的object
*/
private static Object String2Object(String objectString) {
byte[] mobileBytes = Base64.decode(objectString.getBytes(), Base64.DEFAULT);
ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(mobileBytes);
ObjectInputStream objectInputStream = null;
try {
objectInputStream = new ObjectInputStream(byteArrayInputStream);
Object object = objectInputStream.readObject();
objectInputStream.close();
return object;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 使用SharedPreference保存对象
*
* @param fileKey 储存文件的key
* @param key 储存对象的key
* @param saveObject 储存的对象
*/
public static void save(String fileKey, String key, Object saveObject) {
SharedPreferences sharedPreferences = 全局类.getApplicationContext().getSharedPreferences(fileKey, Activity.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
String string = Object2String(saveObject);
editor.putString(key, string);
editor.commit();
}
/**
* 获取SharedPreference保存的对象
*
* @param fileKey 储存文件的key
* @param key 储存对象的key
* @return object 返回根据key得到的对象
*/
public static Object get(String fileKey, String key) {
SharedPreferences sharedPreferences = 全局类.getApplicationContext().getSharedPreferences(fileKey, Activity.MODE_PRIVATE);
String string = sharedPreferences.getString(key, null);
if (string != null) {
Object object = String2Object(string);
return object;
} else {
return null;
}
}
}
- 待保存的Object对象(实现 Serializable )
public class ClassTest implements Serializable {
public String mAppId;
public int mPlatForm;
public List<ClassInner> mList;
public static class ClassInner implements Serializable{
public int id;
public List<ClassInnerOther> mInnerList;
}
public static class ClassInnerOther implements Serializable{
public String name;
public int value;
}
}
ClassTest testClass = new ClassTest();
SharedPreferenceUtil.save("file_key","value_key",testClass );
Object object = SharedPreferenceUtil.get("file_key","value_key");
if(object != null) {
ClassTest testClass = (ClassTest) object;
}